python读取并输出文本文件同时加上行号

 1 def print_to_file(fname):
 2     num = 1
 3     #output_file=open(fname+"_OK.txt","w")
 4 
 5     with open(fname+"_OK.txt","w") as output_file:
 6         with open(fname, ‘r‘) as input_file:
 7             for line in input_file:
 8                 output_file.write(‘%03d %s‘ % (num, line))
 9                 num = num + 1
10 
11 while True:
12     fileName=input("请输入待格式化代码源文件名（含扩展名）：")
13     #print_to_file("test.cpp")
14     print_to_file(fileName)
15     kkk=input("文件格式化输出工作已经完成。是否需要继续格式化其他文件？(Y/N):")
16     if kkk==‘N‘ or kkk==‘n‘:
17         break